Method and apparatus for injecting water or other liquids into gas input wells



W. J. ROBERTS METHOD AND APPARATUS FOR INJECTTNG WATER 0R OTHER LIQUIDS INT0 GAS INPUT WELLS Filed Nov. 23, 1943 V la i5 WATER 1N /x7 I6 n f A Y X V WW WA@ www@ .....y y -v 7"* Av l\,'

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Patented liuly 4, 'QS

unirse STATES kPA'IEN'IA." oFrlcE'ff METHOD AND APPARATUS FOR INJECTING WATER OR OTHER LIQUIDS INTO GAS INPUT WELLS William J. Roberts, deceased, late of Little Chief, Okla., by Bonnie J. Roberts, administratrix,

.McKinney, Tex., assigner to Phillips Petroleum Company, a corporation of Delaware The invention relates to a method and apparatus for injecting water or other liquids into gas input wells. Y

-In the oil producing art, it is now common practice to return to the producing strata, part or all of the gas produced in a given eld, in order that the original pressure of the eld maybe conserved as'much as possible and the yield of crude oil isthereby greatly prolonged. It is also common practice to introduce gas from a nearby or even` a remote field into a so-called input well located in the eld to'be treated. v Y .y

It has under certain circumstances been found advantageous to also introduce Water into certain old elds which are being produced under gas drive, and this ingestion of water has customarily been accomplished by the use of pumps driven by any convenient prime mover. The water, in the case of a gas'drive installation, is introduced for the purpose of preventing or minimizing the tendency of the input gas to channel' the formation and disturb nearby olset wells which mayl or may not belong to the company operating' the input well.

Due to the uncertainty as to the amount of water input that will be necessary to safeguard the formation, the-selection of a, proper size of pump is largely a matter of guesswork and the operator often nds that the original pump must `be replaced by a larger one, or else the original pump chosen is unnecessarily large and must be choked down or else replaced by a smaller, less expensive pump. In any event, the investment represented by any pump regardless of size or type is appreciable, and a great saving may be realized by the use of the present invention which eliminates the use of any pump.

The invention` has for an object, the injection of-.water to an oil bearing formation, for any purview of a well bore fitted in accordance with the invention, the numeral IU indicates a casing `which is tted with an inlet Il for introduction ofr gas under pressure, the inlet usually being provided with a control valve I2. It is pointed out here that in the past, it has been customary to inject water into the conduit I I or correspondingly into the top of the casing I0 by meansof a.: pump. In accordance with the invention, however, there is placed within the casing a string of tubing I3 tted with a back-flow check valve I 4 at the lower end thereof. It must be understood that the tubing ISneed not run all the way to the bottom of the well, need only be run to a depth such that, when lled with water toa point at or near the surface oi"A the ground, the pressure at valve I4 due to the head of water will exceed the gas pressure in casing I0 by an amount at least equal to the closing force of the valve spring. The level of valve I4 in the casing IU hence may be near. the bottom of the Well bore or not, depending upon the relationship between the depth of the well and the pressure existing in the ield at the time pressure flooding is to -be adopted.

rhe water supply line I5 is tted with a valve I 5 for adjusting the rate of water input. The tubing I3 may be continued upwardly as at Il and tted with agate valve I8, if desired, for purposes to be discussed later. t

^ The check valve I4 may be of any approved type, the principal considerations being that the valve disc. i9 should open by pressure, applied from above and should close when .a superior pressure exists below: It preferably should have a spring 2i! urging the valve disc upwardly, or toward the closing position. A ball valve could as well replace the type generally illustrated. In either case, outlets 2| are provided in suicient size and number to provide the required flow- Way.

In operation, gas at the desired pressure is supplied from line II to the interior of casing IU. Water from a reservoir, lake, treating plant or any available source is introduced to tubing I3 from line I5 and under control of valve I6. At first valve I4 will be closed due to the combined forces of spring 2D and of gas pressure in the casing upon the lower side of the disc or ball) I9. Since a column of water 2.31 feet in height exerts a pressure of one pound per square inch, as tubing I3 becomes lled, the head of Water will become great enough to overcome the gas pressure plus the spring pressure and valve member I9 will open, allowing the water to enter the well. The valve member I9 will assume a position or degree of opening proportional to the degree of opening of valve I6, within the range of loading of spring 20. Beyond the range of the spring, that is, when it is fully compressed and valve I4 is fully open, the now will be in proportion to opening of valve I6 Idue to the increase or decreaseof head of the water column in tubing I3. Thus the rate of water input is adjusted from the surface of the ground by manipulation of valve I6. When it is desired to cease injection of water, the same may-be accomplished by closing valve. I6, after which valve I4- will automatically close as soon as the head of water in tubing I3 becomes less than the gas pressure in casing I0.

The level of water in casing lil-will ordinarilybe below the valve I4 and flow is continuous through the tubing I3 as the water is forced into the formation by gas under pressure admitted4 through passage iI. in casing I is maintained abovel the formation pressure.

During operation; pressurei.4

'- llil In the event it becomes necessary topullrtub- I ing I3 to repair valve Ill or for any other reason,

a small portable compressor may be connected totl valve I8. By opening this valve and operating thecompresson: the column4 of water standing;l in=tuloing I3 may be expelled'through valve. I'to the.v casing I0 against thev casing or well pressure.y

The: tubing I3 may then be pulled whileiempty said casing, meansa for supplying.` water to .fsaid` pipe. at a controlledi rate', and. ai spring Apressed. downwardly' opening checkvalve. at the .lower endoi said pipe 'for' supportinga.column of watert inthe pipe,- whereby due: to'zspring pressure Saidi valve will not open unless the pressure in: said*l casing falls .below .the pressure'insaid pipe by an 40 water into a highA pressurexoil` Wellicomprising in.v

combination a pair of concentricitubes the outer' of which provides .a'. well casing.v sealed in said. formation and'having-.a closureat thezupper end,l

f4 said inner tube extending through said closure in sealed relation thereto, means for supplying gas to said casing at a substantially constant rate, means for maintaining a substantially constant head of .Water in. the inner of said tubes, and a spring closed, downwardly opening check valve at the lower end of said inner tube, whereby water is discharged from said inner tube into said well whenever the pressure in said well falls substantially below the hydrostatic pressure of the column'of water held in said inner tube by said ValVel l 3. The method ofinjecting Water into a gastight; well containing gas pressure during a gas drive inagas driven oil neld to reduce gas bypassing for at least a time, which comprises in combination the steps of injecting gas under pressure into said well, injecting Water into said well' against said gas pressure by gravity, and restraining the entrance of water unless its gravity head exceeds said gas pressure by asubstantialamount, whereby blowing of gas into said. gravity head of water is substantially eliminated..

4. A method of reducing gas by-passing while gas drivingga subterranean oil formation, comprising; the steps of supplying gas at a substantially constant rateto a subterranean-oil.forma-v tion under pressure andinjecting water into said formation from a water column when the pres-- sure in said formation falls a predetermined.

amount below the gravity:head of said water column. .i Y

12O1\ll\ll}lI J. ROBERTS,

Administratie@ of the Estate of William. J.

Roberts,` Deceased. f.

REFERENCES CITEDv The-following references areof recordinwv the:

iile of'this patentt' I UNITED STATES. PATENTS-1' l fDate Number f Name.

1,249,232 Squires .,Dec.. 4, 1917 1,511,067 Russell Oct. 7., 1924.- 1,658,305 Russell .Feb. .'7, 1928 2,155,718- Layne. etal. Apr.. 25,1939 2,261,057 v Erwin Oct..28, 1941 Crites` May-2, 1944r 

